Let’s get started…
Earth’s weather is capable of producing a variety of whirling (or tornadic) winds. These include dust devils, waterspouts and tornadoes. Although they share the common element of a rotating column of air, they are actually formed in different ways. Dust devils and small whirlwinds are created by intense local heating of the ground that causes the air to rise rapidly. Tornadoes are caused by the interaction of air current aloft and unceasingly occur in conjunction with severe thunderstorms.
The United States records the most tornadoes in terms of number, but the Netherlands is actually the most tornado prone country based on land place. The prime season for tornadoes in the United States is late winter and spring when atmospheric instability over the US is best.
Tornadoes are produced within thunderstorms. Supercell thunderstorms are most frequently the source of tornadoes, but they can also occur in squall lines and hurricanes.
The actual formation of tornadoes is not yet fully understood. It is thought that high level winds blowing in a different direction from the low level winds causes the entire thunderstorm to rotate. Warm and cold air currents within the storm interact to produce a spinning column of air. The mesocyclone, as the column is known, may produce a wall cloud, a visible sign of a developing tornado.
The spin works its way down the main updraft of the cloud, emerging from the cloud base as a funnel cloud. When the funnel cloud touches the ground, it has become a tornado. Tornadoes take on the color of whatever debris they happen to suck up. It is possible for tornadoes to be invisible or only partially visible, depending on the terrain over which they are moving.
Tornadoes move with their parent thunderstorm. The path of destruction can be from 300 feet to over half a mile wide, and may travel anywhere from a few yards to hundreds of miles. Estimated tornado wind speeds are as high as 300 miles per hour, with updraft speeds up to 180 miles per hour. Tornadoes can last from a few seconds to more than an hour, but the average tornado lasts about 15 minutes.